Vplivi dnevne, nočne in 24-urne sheme snemanja lokacij na ocene velikosti in zgradbe individualnih območij aktivnosti na primeru jelenjadi (Cervus elaphus)v Sloveniji
Most of the previous research on the mammals\u27 home range (HR) is based on diurnal sampling, while the results are often implicitly considered as representative for an entire 24-h period. However, there is a growing body of research on populations, whose habitat selection changes circadianly, which leads to the hypothesis that HR patterns may vary at different periods of the day. This study used 24-h data from 15 red deer equipped with GPS collars to explore differences in the size and composition of their HRs, estimated on diurnal, nocturnal and 24-h samplings. The differences in composition were shown on the forest/non-forest variable. We established that nocturnal, and inparticular the 24-h HRs, largely overlapped with the diurnal HRs (64% and 76%, respectively) and that parts of the HRs that are used exclusively nocturnally are contiguous or adjacent to diurnal HRs. The differences in HR sizes were significant only between diurnal and 24-h HRs. However, the HR composition varied substantially: the average proportion of non-forest areas was 15% in diurnal, 26% in 24-h and 31% in nocturnal HRs. This study demonstrated that with diurnal sampling it is impossible to assess accurately the size and composition of 24-h HRs of red deer in Slovenia. There are several indices that the same is true of several other populations/species. It is therefore important to be aware that HR patterns estimated on the basis of diurnal sampling may be incomplete or even wrong if generalised across the 24-h period.Večina raziskav območij aktivnosti (v nadaljevanju HR) sesalcev temelji na dnevnem vzorčenju lokacij, pri čemer rezultate implicitno pogosto privzemamo kot reprezentativne za celotno 24-urno obdobje. Vendar je raziskanih vse več populacij, pri katerih se habitatni izbor cirkadiano spreminja, kar navaja k hipotezi, da se med deli dneva lahko razlikujejo tudi značilnosti HR. V raziskavi smo na osnovi 24-urne GPS telemetrije 15 osebkov analizirali razlike v velikosti in zgradbi dnevnih, nočnih in 24-urnih HR jelenjadi. Razlike v zgradbi smo prikazali na primeru binarne spremenljivke gozd-negozd. Ugotovili smo, da se nočni in zlasti 24-urni HR pretežno prekrivajo z dnevnimi (64 % oz. 76 % prekrivanje) in da se deli HR, ki jih jelenjad uporablja izključno ponoči, praviloma stikajo z njenimi dnevnimi HR ali pa so v njihovi neposredni okolici (mediana oddaljenosti 125 m). Razlike v velikostih HR so statistično značilne le med dnevnimi in 24-urnimi HR. Močno pa se razlikujejo zgradbe HR: delež negozdnih površin v dnevnih HR znaša 15 %, v 24-urnih 26 % in nočnih HR 31 %, zlasti velik (56 %) pa je v delih HR, ki jih jelenjad uporablja izključno ponoči. Pričujoča raziskava je pokazala, da v Sloveniji z dnevnim spremljanjem ni mogoče točno ugotoviti velikosti, še manj pa zgradbe 24-urnih HR jelenjadi. Več indicev kaže, da je podobno tudi pri mnogih drugih populacijah/vrstah. Zato se je pomembno zavedati, da so lahko značilnosti HR, ki so ugotovljene na osnovi dnevnih spremljav, pomanjkljive ali celo napačne, če jih generaliziramo na 24-urno obdobje